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Lactobacilli Interfere with Streptococcus pyogenes Hemolytic Activity and Adherence to Host Epithelial Cells

Sunil D Saroj1, Lisa Maudsdotter1, Raquel Tavares1

  • 1Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University Stockholm, Sweden.

Frontiers in Microbiology
|August 16, 2016
PubMed

Insights

Certain Lactobacillus strains can inhibit Group A Streptococcus (GAS) virulence by reducing toxin production and adherence. Combinations of these beneficial bacteria show promise for preventing GAS colonization and developing new therapeutics.

Area of Science:

  • Microbiology
  • Immunology
  • Medical Science

Background:

  • Group A Streptococcus (GAS) frequently colonizes the respiratory tract, causing diseases from pharyngitis to toxic shock.
  • Lactobacilli are known to colonize the respiratory tract.
  • Investigating the interaction between Lactobacilli and GAS virulence is crucial for understanding host defense and developing interventions.

Purpose of the Study:

  • To investigate the interference of specific Lactobacillus strains with the virulence phenotypes of Group A Streptococcus (GAS).
  • To determine the effect of Lactobacillus strains on GAS hemolytic activity and adherence to host cells.
  • To explore the potential of Lactobacillus-derived molecules in combating GAS infections.

Main Methods:

  • Assessing the hemolytic activity of S. pyogenes S165 in the presence of different Lactobacillus strains.
  • Analyzing the effect of Lactobacillus conditioned medium on the expression of the streptolysin S (SLS) operon (sag operon).
  • Evaluating the inhibition of GAS adherence to host epithelial cells by individual and combined Lactobacillus species.

Main Results:

  • Lactobacillus rhamnosus Kx151A1 and L. reuteri PTA-5289 inhibited GAS hemolytic activity by decreasing streptolysin S (SLS) production.
  • Conditioned medium from these Lactobacillus strains down-regulated the sag operon transcription.
  • All tested Lactobacillus strains inhibited initial GAS adherence, with combinations being most effective.

Conclusions:

  • Lactobacillus strains can attenuate GAS virulence by reducing SLS production at the transcriptional level.
  • Combinations of Lactobacillus species offer enhanced protection against GAS initial colonization of the pharyngeal mucosa.
  • Lactobacillus-derived effector molecules represent a potential avenue for developing novel therapeutics against GAS infections.
Keywords:
LactobacillusStreptococcus pyogenesadherencemicrobiotastreptolysin

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